Integral Tubular Member and Methods of Manufacturing Same

ABSTRACT

An integral tubular member with at least one integral wear pad is provided. The integral tubular member is formed from a unitary tubular blank having first and second ends and a tube body extending there-between, the tube body being provided with at least one region of a thickened wall to form the at least one wear pad. A method of forming the integral tubular member is provided.

CROSS REFERENCE TO RELATED APPLICATIONS

The present invention claims priority under the Paris Convention to Canadian Patent Application No. 3,003,991, filed on May 4, 2018, the entire contents of which are incorporated herein by reference.

FIELD OF THE DISCLOSURE

The present application relates generally to an integral tubular member and methods of manufacturing an integral tubular member, more specifically an integral tubular member with at least one wear pad and methods of manufacturing an integral tubular member with at least one wear pad.

BACKGROUND

This section provides background information to facilitate a better understanding of the various aspects of the invention. It should be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art.

Standard drill pipe, used in oil and gas drilling operations, consists of a thin walled tube with ends that have been upset and thickened in a forging-like process allowing for two non-integral connector ends to be friction welded on to these ends. These connector ends are typically known as tool joints and are machined to provide threaded. This current manufacturing method of drill pipe requires friction welding and heat treatment technology that does not lend itself to adding features to the tube region of the pipe. In addition, friction welding is a very specialized and expensive process which would be desirable to avoid.

When deployed for use in oil and gas drilling, drill pipes often wear in multiple areas including the tube body and tool joint portions. Therefore, during drilling operations, it is desirable to protect the drill pipe from wear or to slow the rate of wear to prevent premature failure of the drill pipe. Tool joints are generally thick walled elements and thus wear more slowly than the drill pipe and they may be further protected from wear through a hardbanding application. The thin walled tube body, on the other hand, typically cannot be easily protected from wear and, as a result, the tube wall thickness will eventually become too thin and result in the drill pipe being downgraded to a lower class of drill pipe which prevents its further use in many drilling operations.

Previous attempts at preventing drill pipe tube wear include additional components or features being added to the drill pipe after it is manufactured. For example, clamp style centralizers and wear pads have been developed such as that disclosed in U.S. Pat. No. 3,999,811; however, these types of devices may loosen and be displaced along the length of the drill pipe, or may even separate during drilling operations. Adhesive or molded centralizers and wear pads have been developed, such as those disclosed in U.S. Pat. No. 3,697,141 or U.S. Pat. No. 8,119,047; however, these devices invite small regions of corrosion to develop on the pipe wall immediately underneath the devices. This may be due to the presence of small voids in the bonds between the tube and the wear pad feature, which may be filled by wellbore fluid via capillary action, and resulting in corrosion of the metal drill pipe. In addition, it becomes difficult or impossible to properly inspect the thickness or integrity of the tube body itself as these adhesive or molded features are generally immovable.

Thus, it is desirable that the centralizer or wear pad features be integral to the tube body and added or incorporated during manufacturing. One method of accomplishing this is to create a tool joint-like feature in the center of the tube body through upsetting and friction welding a pair of short drill pipe tubes together or friction welding two short drill pipe tubes to a third tool joint-like component between them. Such a method is disclosed in U.S. Pat. No. 8,783,344, which describes utilizing redistributed and upset substrate material and a friction welding process to create a wear pad feature on the drill pipe tube. This method is, however, extremely cost intensive and cumbersome to manufacture as friction welding is a very specialized and expensive process, which would be desirable to avoid. In addition, this method involves the application of a heat treatment step, which results in changes to the material properties of the drill pipe material. In the result, this method would necessitate additional material testing and process validation steps to ensure that the drill pipe meets the required specifications.

BRIEF SUMMARY

In one aspect of the present description, there is provided an integral tubular member formed from a unitary tubular blank, the integral tubular member comprising:

a first end, a second end opposite the first end, and a tube body extending between the first and second ends;

the first and second ends being adapted for connection to other tubular members;

at least one wear pad formed on the tube body, the at least one wear pad comprising a region of increased wall thickness.

In another aspect, there is provided a method of manufacturing an integral tubular member having at least one wear pad, the method comprising:

-   -   providing a tubular blank having a first end, a second end and a         tube body extending between the first and second ends;     -   forming the at least one wear pad by processing at least one         region of the tube body to provide a wall thickness greater than         the wall thickness of the tube body.     -   processing the first and second ends to form, respectively,         first and second connectors, the first and second connectors         comprising means for connecting the integral tubular member to         other tubular members.

In one aspect of this disclosure, there is provided an integral tubular member formed from a one piece blank having a longitudinal axis. The integral tubular member includes an external longitudinal cross sectional profile, an internal longitudinal cross sectional profile, the internal and external cross sectional profiles defining a wall there-between. The wall has varied wall thickness along the integral tubular member with at least three bulges where the wall is thicker than the nominal wall thickness of the tubular member. These bulges may be internal bulges, external bulges, or a combination of both.

In one aspect, there is provided an integral tubular member with at least one integral wear pad formed from a one piece blank having a longitudinal axis, a first end, a second end, a first portion, a central portion, a second portion, an external longitudinal cross sectional profile, an internal longitudinal cross sectional profile, and the internal and external cross sectional profiles defining a wall there-between. The wall has varied wall thickness along the integral tubular member. The first portion of the integral tubular member has at least one internal or external bulge where the wall is thicker than the nominal wall of the integral tubular member, forming an integral connector end with increased strength. The first end of the integral tubular member has a connection feature, the connection feature allowing for the integral tubular member to be coupled to another tubular member. The second portion of the integral tubular member has at least one internal or external bulge where the wall is thicker than the nominal wall of the integral tubular member, forming an integral connector end with increased strength. The second end of the integral tubular member is provided to have a connection feature, the connection feature allowing for the integral tubular member to be coupled to another tubular member. The central portion of the integral tubular member has at least one localized region where the wall is thicker than the nominal wall of the central portion of the integral tubular member, forming at least one integral wear pad.

In one aspect, the at least one wear pad has a metallurgical grain structure and grain direction substantially uniform and unaltered from the one-piece blank substrate.

In one aspect, the at least one integral wear pad has a wall thickness that is between 50-100% greater than the nominal central portion wall thickness.

In a more specific aspect, the at least one integral wear pad has a nominal wall thickness that is between 70-80% greater than the nominal central portion wall thickness.

In one aspect, the ratio of the nominal tube body outside diameter circumference to the tube body transverse cross sectional area is less than or equal to 0.450 in/sq.in and the ratio of the at least one integral wear pad outside diameter circumference to the wear pad transverse cross sectional area is greater than 0.450 in/sq. in.

In one aspect, the nominal integral tubular member tube body wall is equivalent to standard drill pipe tube wall thickness.

In a further aspect, surface hardening or a surface coating is applied to at least one of the at least one wear pads to increase wear resistance.

There is provided a method of manufacturing an integral tubular member. A tube is provided that has an outer wall, a hollow interior, a first end, a second end, a first portion, a central portion and a second portion. The first portion is adjacent the first end, the second portion is adjacent the second end and the central portion is positioned between the first portion and the second portion. The first portion of the tube and the second portion of the tube are upset to form an upset tubular. The upset tubular has an outer wall, a hollow interior, a first end, a second end, a first portion, a central portion, and a second portion. The length of the first portion of the upset tubular has a length of between 25-75% the length of the first portion of the tube. The length of the second portion of the upset tubular has a length of between 25-75% the length of the second portion of the tube. The first portion and the second portion of the upset tubular are processed to form integral connector ends, and the outer wall of the central portion of the upset tubular is processed to form a predetermined outer profile creating an integral tubular member.

In one aspect, the first integral connector end is processed to have a box connection.

In one aspect, the second integral connector end is processed to have a pin connection.

In one aspect, the second integral connector end is processed to have a box connection.

In one aspect, the first integral connector end is processed to have a pin connection.

In one aspect, the predetermined outer profile is substantially cylindrical and uniform

In one aspect, the predetermined outer profile has at least one integral wear pad. The integral wear pad has a wall with increased wall thickness. The integral wear pad may be centrally located on the integral tubular member. The integral wear pad may be a fluted wear pad, a bladed wear pad, a ribbed wear pad or any other type of wear pad known in the art.

In one aspect, the tube is made of steel or aluminum alloy.

There is also provided an additional method of manufacturing an integral tubular member with at least one wear pad. A tube is provided that has an outer wall, a hollow interior, a first end, a second end, a first portion, a central portion and a second portion. The first portion is adjacent the first end, the second portion is adjacent the second end and the central portion is positioned between the first portion and the second portion. The first portion of the tube and the second portion of the tube are upset to form an upset tubular. The upset tubular has an outer wall, a hollow interior, a first end, a second end, a first portion, a central portion, and a second portion. The length of the first portion of the upset tubular has a length of between 25-75% the length of the first portion of the tube. The length of the second portion of the upset tubular has a length of between 25-75% the length of the second portion of the tube. The first portion and the second portion of the upset tubular are processed to form integral connector ends and the outer wall of the central portion of the upset tubular is processed to form a predetermined outer profile. At least one of the first portion, the central portion and the second portion of the upset tubular are processed to have at least one integral wear pad forming an integral tubular member with at least one wear pad.

In one aspect, the first integral connector end is processed to have a box connection.

In one aspect, the second integral connector end is processed to have a pin connection.

In one aspect, the second integral connector end is processed to have a box connection.

In one aspect, the first integral connector end is processed to have a pin connection.

In one aspect, the predetermined outer profile is substantially cylindrical and uniform.

In one aspect, the predetermined outer profile has at least one integral wear pad. The integral wear pad has a wall with increased wall thickness. The integral wear pad may be centrally located on the integral tubular member. The integral wear pad may be a fluted wear pad, a bladed wear pad, a ribbed wear pad or any other type of wear pad known in the art.

In one aspect, the tube is made of steel or aluminum alloy.

There is also provided a method of manufacturing a drill pipe with at least one integral wear pad having a longitudinal axis. A tube is provided that has an outer wall, a hollow interior, a first end, a second end, a first portion, a central portion and a second portion. The first portion is adjacent the first end, the second portion is adjacent the second end and the central portion is positioned between the first portion and the second portion. The first portion of the tube and the second portion of the tube are upset to form an upset tubular. The upset tubular has an outer wall, a hollow interior, a first end, a second end, a first portion, a central portion and a second portion. The length of the first portion of the upset tubular has a length of between 25-75% the length of the first portion of the tube. The length of the second portion of the upset tubular has a length of between 25-75% the length of the second portion of the tube. The outer wall of the central portion of the upset tubular is processed to form a predetermined outer profile having at least one integral wear pad. A tool joint is attached to the first end of the upset tubular and a tool joint is attached to the second end of the upset tubular forming a drill pipe with at least one integral wear pad.

In one aspect, the predetermined outer profile of the outer wall is substantially cylindrical and uniform.

In one aspect, the predetermined outer profile has at least one integral wear pad. The integral wear pad has a wall with increased wall thickness. The integral wear pad may be centrally located on the upset tubular. The integral wear pad may be a fluted wear pad, a bladed wear pad, a ribbed wear pad or any other type of wear pad known in the art.

In one aspect, the tube is made of steel or aluminum alloy.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features will become more apparent from the following description in which references are made to the following drawings, in which numerical references denote like parts. The drawings are for the purpose of illustration only and are not intended to in any way limit the scope of the invention to the particular aspects shown.

FIG. 1 is a side view of an integral tubular member according one aspect of the description, with at least one wear pad.

FIG. 2 is a side cross-sectional view of the integral tubular member of FIG.1.

FIG. 3 is an end view of the tubular member of FIG. 2 taken along section A-A.

FIG. 4 is an end view of the wear pad of FIG.2 taken along section B-B.

FIGS. 5 a, 5 b and 5 c are end views of wear pads according to different aspects, showing different wear pad cross section shapes.

FIG. 6 is a side cross-sectional view of a tube blank.

FIG. 7 is a side cross-sectional view of the tube blank of FIG. 5 following an upsetting step.

FIG. 8 is a side cross-sectional view of the upset tubular of FIG. 7 after a forming step to provide connector ends.

FIG. 9 is a side cross-sectional view of a tubular member according to one aspect, provided with a central integral wear pad.

FIG. 10 is a side cross-sectional view of a tubular member according to one aspect, provided with three integral wear pads.

FIG. 11 is a side view of an integral tubular member according one aspect, having a central integral wear pad.

FIG. 12 is a side view of an integral tubular member according to one aspect, provided with three integral wear pads.

FIG. 13 is a side view of an integral tubular member according to one aspect, provided with five integral wear pads.

FIG. 14 is a side view of an integral tubular member according to one aspect, provided with five integral wear pads of different sizes.

FIG. 15 is a side view of an integral tubular member according to one aspect, provided with three integral wear pads of different sizes.

FIG. 16 is a side view of an integral tubular member according to one aspect, provided with three integral wear pads with different external profiles.

FIG. 17 is a side cross-sectional view of a tube blank, according to one aspect, used to form a tubular member.

FIG. 18 is a side cross-sectional view of tubular member formed from the tube blank of FIG. 16, following an upsetting step.

FIG. 19 is a side cross-sectional view of the upset tubular member of FIG. 18 provided with a central integral wear pad.

FIG. 20 is a side cross-sectional view of the tubular member of FIG. 19 prior to being provided with tool joints at the ends thereof.

FIG. 21 is a side cross-sectional view of a drill pipe with a central integral wear pad formed from the tubular member and tool joints of FIG. 20.

DETAILED DESCRIPTION OF THE PREFERRED ASPECTS

In the following discussion and in the claims regarding the integral tubular member with at least one wear pad, the term “one piece blank” generally refers to the single piece semi-finished tubular member immediately prior to the creation of the at least one integral wear pad. It will be understood that the sequence of manufacturing processes required to create the desired one piece blank may be varied without limiting the scope of the invention. For example, the one piece blank may take the form of a raw unprocessed tube or a pre-processed tube that has been put through upsetting, forming, heat treatment, machining, welding or any other process known in the art to produce the desired geometry of the one piece blank. Reference to “one piece blank substrate” in regards to metallurgical properties and metallurgical grains should be interpreted as the metallurgical properties and grains of the one piece blank immediately prior to creating the at least one wear pad feature. It should not be interpreted to indicate the metallurgical substrate properties during any sequence of manufacturing processes which may occur to create the desired one piece blank. Also, the term “wear pad” should be interpreted in the broadest sense possible to describe features which act sacrificially in slowing, delaying, or otherwise preventing the downgrading of a tubular member due to thinning of wall thickness drilling operations. Such wear pad features are substantially cylindrical in nature and may include features such as flutes, blades, ribs, external bulges, internal bulges, a combination of any such features or any other drilling operations wear features known in the art. Any description of features utilizing sequencing as “first”, “second”, “third” etc. is done for the purpose of clarity in describing relative locations and relationships between features and should not be interpreted to imply any ordering, capability, priority or physical location of features relative to a borehole or other external frames of reference.

The term “tubular member” generically refers to the components which make up a typical drill string such as the Bottom Hole Assembly (BHA), Heavy Weight Drill Pipe (HWDP), drill pipe, or any similar components which can replace such components in form and/or function. When describing a specific feature or aspect of the invention the term “integral” refers to the feature or aspect being present on, or, in particular, created from, a substantially one piece blank without attachment methods employed. It will be understood that specific features and aspects such as wear pads may be integral while other features such as tool joints may not be integral without affecting the scope of the invention.

The term “integral tubular member” refers to a component which can be utilized to form a drill string and which is created from a one piece blank. A “drill pipe” or similar tubular member would typically be created from multiple components.

The term “connector end” refers to an end region of a tubular member having increased wall thickness to allow for connection features such as threads to be manufactured thereon. Further, the term “tool joint” generally refers to a non-integral connector end but which are attached or secured thereto. Tool joints are typical components of a finished drill pipe assembly.

An integral tubular member with wear pad will now be described with reference to FIG. 1 to FIG. 5.

With reference to FIG. 1 and FIG. 2, an integral tubular member 100 with at least one wear pad 24 is formed from a one piece blank having a longitudinal axis. As will be understood from the present description, although one wear pad 24 is shown in FIG. 1 and FIG. 2, the description is not limited to such single wear pad and the tubular member 100 may be provided with any number of wear pads. The integral tubular member 100 includes an external longitudinal cross sectional profile 102 and an internal longitudinal cross sectional profile 104 which together define a wall 106 there-between. The wall 106 has a varied thickness along the length of the tubular member. The internal cross-sectional profile 104 also defines a bore or hollow interior 14 extending along the length of the integral tubular member. The integral tubular member 100 with at least one wear pad 24 is generally cylindrical in shape, its transverse cross section along its length being generally circular in nature as shown in FIG. 3. As also shown, the inner diameter of the integral tubular member varies along its length. It will be understood that other transverse cross section shapes and any combination of transverse cross section shapes may be possible within the integral tubular member 100 without affecting the scope of the present description. The wall 106 of the integral tubular member 100 is varied in thickness to create localized wear resistance and structural enhancement. An increase in thickness can either be: a localized increase to the external diameter, resulting in an exterior bulge; a localized decrease to the internal diameter, resulting in an interior bulge; or a combination of both. These variations in wall thickness are shown in FIG. 2.

Referring to FIG. 1 and FIG. 2, the integral tubular member 100 with at least one wear pad 24 has a first end 16, a second end 18, a first connector end 20, a second connector end 22, a nominal tube body 110 and at least one wear pad 24. The nominal tube body 110 has an external diameter D1 and an internal diameter d1, forming a wall there-between 106 with thickness t1. The first connector end 20 has an external diameter D3, and internal diameter d3, forming a wall there-between 106 with an increased thickness t3 to allow for adding a first connection feature 108. As shown, the first connection feature 108 comprises a thread provided on the internal wall thereof, resulting in a “box” end, as is known in the art. The second connector end 22 has an external diameter D4 and an internal diameter d4, forming a wall 106 with an increased thickness t4 to allow for adding a second connection feature 112. The second connection feature 112 comprises a thread provided on the external wall thereof, resulting in a “pin” end, as is known in the art. The first connector end 20 and second connector end 22 may be formed by an external diameter increase, an internal diameter increase, or a combination of both.

The connection features 108, 112 allow for one tubular member to be coupled to another similar or dissimilar drilling tubular member. The first connection feature 108 is shown as a box thread rotary shouldered connection. The second connection feature 112 is shown as a pin thread rotary shouldered connection. It will be understood by a person skilled in the art that other designs and configurations of connection features may be possible without affecting the scope of the present description.

The nominal tube body 110 is provided with at least one integral wear pad 24 having an external diameter D2 and an internal diameter d2, there-between forming a wall 106 of increased thickness t2. As discussed herein, the wear pad 24 serves to enhance wear resistance of the tubular member. It will be understood that the at least one wear pad 24 may be formed by an external diameter increase, an internal diameter increase, or a combination of both. The integral wear pad 24 may be substantially cylindrical in shape, having a transverse cross section A2 along its length being generally circular as shown in FIG. 4. It will be understood that other transverse cross section shapes, and any combination of transverse cross section shapes, may be possible for one or more of the at least one wear pads 24, with each shape being independent of the other. Referring to FIG. 5, that is, FIGS. 5a to 5 c, a variety of transverse cross section shapes are shown which may be desirable in any combination for any one of at least one integral wear pads 24 depending on end-use requirements. It will be understood by a person skilled in the art that the transverse cross sections in FIGS. 5a to 5c are presented for illustrative purposes and are not to be construed to limit the scope of the invention to the shapes shown.

Referring to FIG. 2, in the aspect shown, the wall 106 varies such that t1<t2<t3=t4. It will be understood by a person skilled in the art that it is only necessary that t2 is greater than t1 to form at least one wear pad in order to enhance wear resistance and that the wall thickness t3 and t4 may vary based on end-use requirements without affecting the scope of the present description.

Referring to FIG. 2, in the aspect shown, the external longitudinal cross section 102 varies such that D1<D2<D3=D4. It will be understood by a person skilled in the art that, for the purpose of the present description, D2 is preferably equal to or greater than D1, and that the external diameters D3 and D4 may vary based on end-use requirements without affecting the scope of the present description.

Referring to FIG. 2, in the aspect shown the at least one integral wear pad 24 is shown as a single integral wear pad located generally in the center of the integral tubular member 100. It will be understood that one or more wear pads 24 may be integrally present in any number of locations along the length of the nominal tube body 110, each with an individual external diameter D2, internal diameter d2, wall thickness t2, and transverse cross section shape A2, which may be the same or different.

In one aspect the at least one wear pad 24 has a wall thickness t2 that is between 50-100% greater than the nominal tube body 110 wall thickness t1. In another aspect the at least one wear pad 24 has a nominal wall thickness t2 that is between 70-80% greater than the nominal tube body 110 wall thickness t1.

In one aspect the ratio of the nominal tube body circumference formed by outside diameter D1 to the nominal tube body cross sectional area formed by D1 and wall thickness t1 is less than or equal to 0.450 in/sq.in and the ratio of the at least one wear pad circumference formed by outside diameter D2 to the wear pad cross sectional area formed by D2 and wall thickness t2 is greater than 0.450 in/sq. in.

In another aspect, the metallurgical grain structure and grain direction of the at least one wear pad 24 is substantially unaltered from the one piece blank substrate.

In another aspect, the at least one wear pad 24 is not formed through a redistribution of the one piece blank substrate material.

In one aspect the tube body wall thickness t1 is equivalent to standard drill pipe tube thickness.

In one aspect, on or more of the wear pads 24 may be treated to increase wear resistance by means of a surface hardening treatment, including providing a surface coating. Various other surface treatments are known in the art to increase wear resistance of the wear pads.

A method of manufacturing integral tubular members of the present description will now be discussed. In this discussion, the term “tube” or “tube blank” is used to describe an initial tubular element having a longitudinal axis, external and internal longitudinal cross-sectional profiles defining a wall there-between and the tube wall having a wall thickness which is generally constant along its length. It will be understood that the tube may, in one aspect, be pre-processed, or “tuned”, with regards to creating or forming the desired material properties and geometry. Further, the term “upset tubular” is used to describe a semi-finished tubular with a longitudinal axis having external and internal longitudinal cross sectional profiles defining a wall there-between and the upset tubular wall having a wall thickness which is varied along the upset tubular. It is typical that this varied wall thickness is predominantly at the ends of the upset tubular, resulting in the ends having thicker wall portions; however it will be understood that the varied wall may be present in any location of the upset tubular and may exist as an increase or decrease in wall thickness. The term “processing” is used generally to describe manufacturing methods known in the art which act to create dimensional features either through the removal of, addition to, or forming of substrate material. Such processes may include but are not intended to be limited to lathe machining, milling, grinding, welding, cold working, forging, burnishing, etc.

A method of manufacturing an integral tubular member 10 will now be described with reference to FIGS. 6 to 16.

Referring to FIG. 6 and FIG. 7, manufacturing of integral tubular member begins with a tube 40 that has an outer wall 42, a hollow interior 44, first end 46, a second end 48, a first portion 50, a central portion 52 and a second portion 54. First portion 50 is adjacent first end 46, second portion 54 is adjacent second end 48 and central portion 52 is positioned between first portion 50 and second portion 54. As is common, tube 40 may, for example, be made of steel or an aluminum alloy. The present description is not limited to any particular material. It will be understood by a person skilled in the art that tube 40 may be a raw unprocessed tube or may be pre-processed through forming, heat treatment, machining, welding or any other process known in the art. Tube 40 may be made thicker than a conventional drill pipe tube body prior to processing to allow for excess material to be removed during later processing of upset tubular 60, as shown in FIG. 7.

In one step of the present method, first portion 50 of tube 40 and second portion 54 of tube 40 are upset to form an upset tubular 60, shown in FIG. 7. As used herein, the term “upset” or “upsetting” generally refers to a method or process, as known in the art, where the wall thickness and thus transverse cross sectional area of a portion of a tubular member is increased beyond that of the initial nominal wall thickness and transverse cross sectional area. A person skilled in the art will understand how the upsetting process works and the different methods of achieving the upset tubular 60 shown in FIG. 7.

One method of upsetting tube 40, shown in FIG. 6, is to use a controlled and hydraulically driven upsetting method. First portion 50 of tube 40 is heated. An inner diameter mandrel is inserted into first end 46 and an outer diameter die is positioned around the outside of first portion 50. An annular forging head is used to force first end 46 to fill the annular volume between the inner diameter mandrel and outer diameter die. This method of upsetting is known in the art and it is to be understood that different upsetting methods may be used. Second portion 54 would be upset in a similar manner. The upsetting process may be achieved in one or many cycles depending upon the final desired outer diameter, inner diameter, overall portion length change, final portion lengths of upset tubular and final desired length of upset tubular.

Processing of tube 40 may involve the removal of material through the use of a lathe or milling process or may allow for additive or forming methods of manufacture. For example, a wear pad 24, shown in FIG. 9, could be built up with weld overlay on tube 40, shown in FIG. 6, or upset tubular 60, shown in FIG. 7, or on integral tubular member 10 shown in FIG. 8. Tube 40 may be formed, drawn, forged or burnished to reduce the outer diameter and wall thickness around one or more of the wear pads 24.

Referring to FIG. 7, first portion 62 of upset tubular 60 may have a length of between 25-75% the length of first portion 50 of tube, or tube blank, 40, shown in FIG. 6. Similarly, second portion 64 of upset tubular 60 may have a length of between 25-75% the length of second portion 54 of tube 40, shown in FIG. 6. Referring to FIG. 7, upset tubular 60 has an outer wall 66, a hollow interior 68, a first end 70, a second end 72, a first portion 62, a central portion 74 and a second portion 64. First portion 62 is adjacent first end 70, second portion 64 is adjacent second end 72 and central portion 74 is positioned between first portion 62 and second portion 64. First portion 62 and second portion 64 of upset tubular 60 are processed to form integral connector ends 20 and 22 shown in FIG. 8. Processing of first portion 62 and second portion 64 of upset tubular 60 may include machining of hollow interior 68 and outer wall 66 to create appropriate connector ends 20 and 22, shown in FIG. 8. Connector ends 20 and 22 are functionally tool joints and include the outer diameter, inner diameter, taper, inner diameter transitions, hardbanding features and any other feature known in the art. Connector ends 20 and 22 may include box or pin connections. Once connector ends 20 and 22, shown in FIG. 8, have been formed, outer wall 66 of central portion 74 is processed to form a predetermined outer profile. A metal lathe or other machining tool may be used to machine outer wall 66. Outer wall 66 may be processed into a substantially cylindrical and uniform wall or may have integrally formed wear pads depending upon the needs of the user.

Referring to FIG. 8, an integral tubular member 10 has an outer wall 12, hollow interior 14 with a first end 16 and a second end 18. First end 16 has a first connector end 20 and second end 18 has a second connector end 22. Connector end 20 and connector end 22 are, in one aspect, integrally formed on integral tubular member 10. In the aspect shown, first connector end 20 has a “box” connection and second connector end 22 has a “pin” connection end. As discussed above, and as would be understood by persons skilled in the art, first connector end 20 and second connector end 22 are configured to allow for connection of the first or second connector end of an integral tubular member to the corresponding connector end of another drill string tubular. It will be understood by a person skilled in the art that integral tubular member 10 may have different types of connection ends depending on the type of connection required for any given drill string. For example, integral tubular member 10 may have two box connections, two pin connections or may have one box connection and one pin connection.

As would be understood, with integral connector ends 20 and 22, there is no need to utilize friction welding and weld heat treatments to create a drilling tubular.

Referring to FIG. 9, integral tubular member 10 may also have an integral wear pad 24. In the aspect shown, integral wear pad 24 is located generally centrally along integral tubular member 10; however, it will be understood by persons skilled in the art that integral wear pad 24 may be positioned anywhere along the length of the integral tubular member 10. Referring to FIG. 10 through FIG. 16, different aspects of integral wear pads 24 are shown. As can be seen, different sizes of wear pads 24 and different numbers of wear pads 24 may be used. Wear pads 24 may be fluted, bladed, ribbed, spiraled or any other type of wear pad 24 known in the art.

Integral tubular member 10 is manufactured in a way that allows connector ends 20 and 22 and wear pad 24 to be integrally created. This avoid the need for expensive friction welding and welding heat treatments to create a drilling tubular and allows for a wear pad 24 to be included integrally without attempting to incorporate a separate wear pad onto a tubular member.

Referring to FIG. 9 through FIG. 16, wear pads 24 may be integrally formed and may have different shapes. Wear pads 24 may be cylindrical, fluted, bladed, ribbed or may have any other suitable shape known in the art. It will be understood that outer wall 66 of central portion 74 may be processed to form a predetermined outer profile before first portion 62 and second portion 64 are processed to form connector ends 20 and 22. It may be beneficial to process central portion 74 prior to processing first portion 62 and second portion 64 as an error made to central portion 74 is less likely to be fixable than an error made to first portion 62 or second portion 64.

An alternative method of manufacturing a drilling tubular will now be described with reference to FIG. 17 through FIG. 21.

Referring to FIG. 17, manufacturing of drill pipe with at least one integral wear pad begins with a tube, or tube blank 40 that has an outer wall 42, a hollow interior 44, first end 46, a second end 48, a first portion 50, a central portion 52 and a second portion 54. First portion 50 is adjacent first end 46, second portion 54 is adjacent second end 48 and central portion 52 is positioned between first portion 50 and second portion 54. As discussed above, tube 40 may be made of any material, such as steel or an aluminum alloy. It will be understood by a person skilled in the art that tube 40 may be a raw unprocessed tube or may be pre-processed through forming, heat treatment, machining, welding or any other process known in the art.

In a first step, first portion 50 of tube 40 and second portion 54 of tube 40 are upset to form an upset tubular 80, as shown in FIG. 18. A person of skill in the art will understand how the upsetting process works and different methods of achieving the upset tubular 80 shown in FIG. 18. Such methods were also discussed above.

Referring to FIG. 18, first portion 82 of upset tubular 80 may, in one aspect, have a length of between 25-75% the length of first portion 50 of tube 40, shown in FIG. 17. Similarly, second portion 84 of upset tubular 80 may have a length of between 25-75% the length of second portion 54 of tube 40, shown in FIG. 17. Referring to FIG. 18, upset tubular 80 has an outer wall 86, a hollow interior 88, a first end 90, a second end 92, a first portion 82, a central portion 94 and a second portion 84. First portion 82 is adjacent first end 90, second portion 84 is adjacent second end 92 and central portion 94 is positioned between first portion 82 and second portion 84. Outer wall 86 is processed to form a predetermined outer profile. In the aspect shown in FIG. 19, the outer profile includes an integrally formed wear pad 200. It will be understood that outer profile may be substantially cylindrical or may have a number of integral wear pads 200 with different features as shown in FIG. 11 through 16. A metal lathe or other machining tool may be used to machine outer wall 86 of first portion 82, central portion 94 or second portion 84. First portion 82 and second portion 84 may be processed to prepare first end 90 and second end 92, respectively, for attachment of tool joints.

Referring to FIG. 20, in the aspect shown, a box connection tool joint 202 and a pin connection tool joint 204 are provided for attachment to first end 90 and second end 92 of upset tubular 80 to create a finished drill pipe with integral wear pad 10, shown in FIG. 21. It will be understood by a person of skill in the art that different types of tool joints with any type of connection features may be used depending upon the requirements of the user without altering the scope of the invention. The term “attach” should be interpreted in a general sense to refer to the permanent or semi-permanent affixing of tool joints to the upset tubular. Attachment of box connection tool joint 202 and pin connection tool joint 204 may be performed through welding, threading, press/shrink fitting, gluing/bonding/adhesive or any combination of these, or any other attachment methods known in the art without affecting the scope of the invention being disclosed. Referring to FIG. 21, in the aspect shown, drilling tubular 10 has an outer wall 12, a hollow interior 14, a first end 16 and a second end 18. A box connection tool joint 202 is positioned at first end 16 and a pin connection tool joint 204 is positioned at second end 18. Drilling tubular 10 has an integral wear pad 200.

Any use herein of any terms describing an interaction between elements is not meant to limit the interaction to direct interaction between the subject elements, and may also include indirect interaction between the elements such as through secondary or intermediary structure unless specifically stated otherwise.

In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.

It will be apparent that changes may be made to the illustrative aspects, while falling within the scope of the invention. As such, the scope of the following claims should not be limited by the preferred aspects set forth in the examples and drawings described above, but should be given the broadest interpretation consistent with the description as a whole. 

1-17. (canceled)
 18. An integral tubular member formed from a one piece blank, the integral tubular member defining a longitudinal axis along its length, the integral tubular member having a first end, a second end opposite the first end, a first integral connector end adjacent the first end, a second integral connector end adjacent the second end, a tube body located between the first connector end and second connector end, the first connector end having a first wall thickness, a first outer diameter, and a first inner diameter, and the second connector end having a second wall thickness, a second outer diameter, and a second inner diameter, the tube body having a third wall thickness, a third outer diameter, a third inner diameter, and at least one region of locally increased wall thickness forming at least one wear pad, the at least one wear pad having a fourth wall thickness, a fourth outer diameter, and a fourth inner diameter, the fourth wall thickness being greater than the third wall thickness, the at least one wear pad having a metallurgical grain structure and grain direction substantially uniform and unaltered from the one piece blank substrate.
 19. The integral tubular member of claim 18, wherein the at least one integral wear pad has a fourth wall thickness that is between 50-100% greater than the third wall thickness.
 20. The integral tubular member of claim 18, wherein the at least one integral wear pad has a fourth wall thickness that is between 70-80% greater than the third wall thickness.
 21. (canceled)
 22. The integral tubular member of claim 18, wherein the ratio of the circumference formed by the third outside diameter to the transverse cross-sectional area formed by the third outside diameter and the third wall thickness is less than or equal to 0.450 in/sq.in. and, the ratio of the circumference formed by the fourth outside diameter to the transverse cross-sectional area formed by the fourth outside diameter and the fourth wall thickness is greater than 0.450 in/sq. in.
 23. The integral tubular member of claim 18, wherein the third wall thickness is substantially equivalent to a standard drill pipe tube thickness.
 24. The integral tubular member of claim 18, wherein the first connector end is provided a first threaded connection and the second connector end is provided a second threaded connection.
 25. The integral tubular member of claim 24, wherein the first threaded connection is a box connection.
 26. (canceled)
 27. The integral tubular member of claim 25, wherein the second threaded connection is a pin connection.
 28. (canceled)
 29. A method of manufacturing an integral tubular member having at least one wear pad, the method comprising: providing a tubular blank having a first end, a second end and a tube body extending between the first and second ends; forming the at least one wear pad by processing at least one region of the tube body to provide a wall thickness greater than the wall thickness of the tube body. processing the first and second ends to form, respectively, first and second connectors, the first and second connectors comprising means for connecting the integral tubular member to other tubular members.
 30. The method of claim 29, wherein the at least one region is formed with an outer diameter that is equal to or greater than the outer diameter of the tube body.
 31. (canceled)
 32. The method of claim 29, wherein the step of forming the at least one wear pad comprises reducing the wall thickness of the tube body in regions adjacent the at least one wear pad. 33-39. (canceled)
 40. The method of claim 29, wherein the step of forming the at least one wear pad is performed without redistributing material of the tubular blank.
 41. The method of claim 29, wherein step of forming the at least one wear pad is performed without altering the metallurgical grain structure and grain direction of the tubular blank.
 42. A method of manufacturing an integral tubular member having at least one wear pad, comprising the steps of: providing a tube having an outer wall, a hollow interior, a first end, a second end, a first portion, a central portion and a second portion, the first portion being adjacent the first end, the second portion being adjacent the second end and the central portion being positioned between the first portion and the second portion; upsetting the first portion of the tube and the second portion of the tube to form an upset tubular having an outer wall, a hollow interior, a first end, a second end, a first portion, a central portion and a second portion, the first portion of the upset tubular having a length of between 25%-75% of the length of the first portion of the tube and the second portion of the upset tubular having a length of between 25%-75% of the length of the second portion of the tube; processing the first portion and the second portion of the upset tubular to form integral connector ends; and processing the central portion of the upset tubular to form a predetermined outer profile, the central portion of the upset tubular being processed to have at least one integral wear pad. 43-50. (canceled)
 51. A method of manufacturing a drilling tubular, comprising the steps of: providing a tube having an outer wall, a hollow interior, a first end, a second end, a first portion, a central portion and a second portion, the first portion being adjacent the first end, the second portion being adjacent the second end and the central portion being positioned between the first portion and the second portion; upsetting the first portion of the tube and the second portion of the tube to form an upset tubular having an outer wall, a hollow interior, a first end, a second end, a first portion, a central portion and a second portion, the first portion of the upset tubular having a length of between 25%-75% of the length of the first portion of the tube and the second portion of the upset tubular having a length of between 25%-75% of the length of the second portion of the tube; processing the outer wall of the upset tubular to form a predetermined outer profile; attaching a tool joint to the first end; and attaching a tool joint to the second end.
 52. (canceled)
 53. The method of claim 51, wherein the predetermined outer profile has at least one integral wear pad. 54-58. (canceled) 